The Department of Religious Art and Mosan Art is partly the heir to the Museum of Religious Art and Mosan Art (MARAM), which was the successor to the former diocesan museum, whose mission it has retained: it aims to receive works of art from the the diocesan patrimony, in order to ensure their safety and conservation.
It brings together the old diocesan collections and those dedicated to the same speciality of the Museum of Archaeology and Decorative Arts and the Liège Archaeological Institute, for the sake of complementarity.
The MARAM was created based on several funds, the oldest and most important of which came from the founding art society. The latter benefited from important donations and legacies, including that of Abbot Scheen, who was heir to Jules Helbig, to whom the museum is indebted for his rich collection of Flemish Primitives. The institution has been enriched by donations from various sources. It also preserves the archives of the Osterrath glassmakers and the Dehin goldsmiths.
The department's vocabulary reflects the double focus of its collections: on the one hand, the evocation of Mosan art, on the other, the major artistic expression of the golden age of the diocese of Liège (11th–13th centuries). The department also offers a clear overview of the evolution of religious art from the early Middle Ages to the beginning of the 20th century, through some of the most important pieces in Belgium in the fields of sculpture, goldsmithing and painting. Regional art works share space with masterpieces from the Flemish, French, Italian, Brabant and German schools.